


A Little Help

by FullOfBoredom



Category: Undertale (Video Game)
Genre: Egg Laying, Eggpreg, M/M, Nightkiller - Freeform, Oviposition, Tentacle Sex, killermare - Freeform
Language: English
Status: Completed
Published: 2021-01-24
Updated: 2021-01-24
Packaged: 2021-03-16 02:14:10
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 8,182
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28948746
Author URL: https://archiveofourown.org/users/FullOfBoredom/pseuds/FullOfBoredom
Summary: “If you come into this room, your life is forfeit.”Alright, maybe a bit of recon. Ream Nightmare after his little getaway. He gently slid the door open to the main room, trying to get a peek.Holy shit.From the door, Nightmare couldn’t see him, not easily, but from this angle, Killer could see a fuckton of him. He was positioned onto his hands and knees, having settled his chest onto a footrest to keep him upright. His one cyan eye was lolled back into his skull, a tentacle slowly thrusting down his throat, Nightmare’s mouth open and drooling around it.
Relationships: Sans/Sans (Undertale)
Comments: 10
Kudos: 130





	A Little Help

Nightmare casually strode down the halls of the castle (he hoped), heading deep into the bowels of the sprawling building. His steps were quick but confident. To the others, it would appear he was in a decent mood, tentacles writhing to a beat they couldn’t hear, conducting a symphony of chaos as he walked down to the deepest room he could find.

It wasn’t a very large room, practically an apartment with the lack of space it provided. 

But Nightmare didn’t need space for the coming event. Merely privacy.

This room was soundproofed. He’d gone over many times, with each of them, that this place wasn’t to be intruded on under pain of death, and any violation would be grounds for dusting on sight unless the entire castle was taken down to this specific space. It had few amenities, a bathroom, a supply of food, but it would serve the purpose it was meant for. He had almost made it into said room when Killer interrupted him.

“Hey Boss. What’s the orders before your little soul cleanse?” Killer’s crooked grin lazily tilted on his face, soul shaking in excitement. Nightmare usually gave them a more in depth assignment while he was occupied; they’d destroy the place otherwise.

“I can feel those idiots brightening several AUs by Cross’s home line. As the right hand, I expect you can direct who to cause negativity where. I will know if you fail me before I open that door, so do try not to disappoint.” Nightmare glared with his single cyan eye. Killer shrugged, though Nightmare keeping his tentacles to himself was new for him.

“Yeah, yeah. Not your usual, but I gotcha.” His soul beat erratically in his chest, the thrill of the coming chaos already making his LV go wild. “I don’t know why you have these cleanses every couple months alone down here. It’s not like we’d bite.” Nightmare unamused eye didn’t offput Killer. “Well, I would, but I promise you’d like it Boss.” He chuckled, but Nightmare held the glare. While Killer was his top pick for second in command, that also sometimes went to his ego, and he couldn’t have that now, could he?

He hoisted Killer up with a single hand.

“I do them alone as I am very liable to kill you, regardless of standing. I don’t particularly enjoy it either, but I assume you’d all like to keep your heads attached.” Killer’s eyes widened manically, almost salivating under the threat.

“I’d let you take my head however you wanted.” Nightmare tossed him back from the innuendo. Killer landed gracefully.

“Regardless, let me reiterate. _If you come into this room, your life is_ _forfeit_.”

And with a turn, he walked towards the entrance. His voice drifted behind him to the skeleton laying on the floor.

“Have fun.”

He’d no sooner got inside the door, gently closing it from Killer’s perspective, than collapsed on the ground. He locked the thing quickly. His tentacles had already started to get handsy, sliding down his limbs hastily in an attempt to remove his clothes.

Keeping them still before entering this room had taken far more strength than he’d like to admit. He double checked the door lock, going for the magical switches when he felt the first one dip into his pants.

“Haaa-aaah.” It rubbed eagerly along his pelvis. Nightmare kept shedding clothes as fast as he could with them interrupting.

Soul cleanse? A convenient lie. They knew his soul was different from others, so he latched onto the convenient excuse that his soul needed special upkeep and that evening out his moods and body took time after such a thing. He wouldn’t be able to face them if they knew what was actually happening.

Now that his bones were stripped clean, the tentacles got to work. At first when this happened, they’d bind him as he fought and screamed. Now that he’d given into them, he had more control, being able to even make it here and save further clothes from being ruined. They slithered up each limb individually, smaller ones forming beyond his main set, directing him to better positions for access. He didn’t avoid summoning his ecto body, but didn’t try to rush this either. As an inescapable rhythm, he’d learned to find some enjoyment in what he had to endure anyway and the second it formed, they’d rush him. He may be cooperating, but they’d have to work for it like anyone else.

His eyes flicked to the switches by the door. He hadn’t been able to flip them all.

They mostly set up a barrier to keep out prying eyes, like his brother and his group, but also prevented shortcuts. Each one served a purpose. From here, he could see that only one was left. The teleport barrier. Well, only his squad even knew where he was, and even fewer the exact room location, and they’d never attempted to enter before (none of them had the telltale shock symptoms the barrier generated when Nightmare left). He relaxed his body. It’d be fine. They’d be busy for the short while he’d be in here anyway.

—

Killer really hated the cleanses.

He’d set up the group with assignments, but even then, there were more of them than AUs to bother, so in the end, Killer was still stuck in the castle while everyone else got to go cause trouble. Being the Boss was boring. Sitting and doing paperwork just wasn’t for him.

He’d probably killed less than an hour since Nightmare had entered the room, and already he was _dying_ for him to come out. What the hell could his weird apple soul need so often?

Oh he knew about the apple soul. He knew that Nightmare looked different under the black crap too. Out of all of them, Killer probably knew the most (or second most, but he didn’t want an annoying ghost spy anyway). Hurt a little that Nightmare was keeping it from him, considering he shared everything else without question.

He went down to the chamber outside the small room. It was magically charged, Killer could sense it from here. Maybe he’d make himself at home for when Nightmare finally emerged?

Not that he needed the dark monster’s attention, just wanted it, was a selfish bitch that way. And he was more than willing to return the favor! He could lavish attention when he focused, when he wanted! He just usually would rather cause suffering, though Nightmare liked that about him anyway.

God, what the fuck was he doing in there?

He’d never tried porting straight in. Nightmare had made the death threat very clear, and as much slack as he got, he didn’t think he could actively disobey and live. But on the other hand, so fucking bored! 

The barrier would supposedly stop him anyway, but fuck it, maybe he’d try it for kicks. A little zap might be good for him: rile him up, send him in a frenzy to some poor unsuspecting AU. He pictured the little room in his head. Maybe the bedroom off to the side? He could possibly get a peek and leave if Nightmare wasn’t in there, and then he could still go terrorize under the high of getting an answer to this fucking high and mighty secret his boss was keeping.

Bracing himself for the zap, he snapped his fingers.

The first thing he noticed was the noise. His eyes took in the bedroom, that he’d actually landed inside, but that was secondary. The entire room echoed soft pants and whines from the main room. 

The second thing was the _smell_. Heady and thick, it stuck to his nose, a single whiff making his mouth water. 

Did Nightmare lock himself in here to fucking _pleasure himself_ every few months?! He’d heard of pent up, but come on! Killer coulda helped plenty with this, helped his sexy leader relieve a little tension. Half the team would die for the chance to say they tapped that. His first instinct was to throw the door open and slyly insinuate joining, but that line from earlier drifted across his thoughts the second he touched the doorknob.

“ _If you come into this room, your life is forfeit_.” 

Alright, maybe a bit of recon. Ream Nightmare after his little getaway. He gently slid the door open to the main room, trying to get a peek.

Holy shit.

From the door, Nightmare couldn’t see him, not easily, but from this angle, Killer could see a fuckton of him. He was positioned onto his hands and knees, having settled his chest onto a footrest to keep him upright. His one cyan eye was lolled back into his skull, a tentacle slowly thrusting down his throat, Nightmare’s mouth open and drooling around it.

But that didn’t compare to the two tentacles thrusting into his openings. There was a thinner, smoother one keeping time with the one in his mouth, but in his ass, just there to keep stimulation going. But the other one had gotten thicker, more so than usual and was buried deep in his tight little cunt. He could see it sunk into his physical ecto, locked into place. 

He watched in fascination as a wave slipped down the tentacle in question, like something was lodged inside and descending, pausing briefly right at Nightmare’s entrance. 

The tentacle twitched, the bulge passing through whilst Nightmare moaned loudly around his full mouth. He whined as the wave finished it’s journey, depositing a round black egg directly into his cyan ecto, bulging it out from its flat state. Another wave descended down, Nightmare’s eye rolling further into the back of his head when it was pushed in, his body jolting as it forced its way inside. Another smooth egg dropped into him. Nightmare wiggled his body a little, the fourth tentacle getting the picture and massaging his belly to settle things more comfortably into place.

Killer’s mouth had gone dry from hanging open. Hearing Nightmare make those sounds was doing horrible things to his person, his soul erratically flickering at the idea of it.

He watched quietly as the third, fourth, and fifth eggs deposited themselves into Night’s stomach, each pushing his ecto body out a little further than before. He could feel his ecto was already summoned under his hoodie and shorts.

When the sixth egg popped into Nightmare’s body, Killer groaned at the tears just starting to gather in the corner of Night’s eye.

And while Nightmare was gone, he wasn’t the damn boss for nothing, and his eye shot open instantly at the sound. His gaze locked onto Killer in an instant, eyes turning harder than Killer had ever seen ‘em. The tentacle in his mouth pulled out instantly.

“What the _FUCK_ are you DOING IN HERE?!” His voice was scratchy, unable to use it besides moaning for over an hour now. 

The free tentacle snatched Killer instantly, crushing around his midsection with ease and yanking him into the room with Nightmare. Night sat up a little, unable to truly be free while his body went through this ordeal, but one tentacle was enough for any of them when Nightmare felt serious, especially caught off guard.

“I’M GOING TO _KILL YOU_ , AND IT WILL BE _PAINFUL_ , YOU MISERABLE-” Nightmare bit down hard, stopping the wanton moan from the next egg popping in, turning it into a growl. Killer’s frown flipped into something else.

“Fuck that’s hot.” Nightmare flushed indignantly, tightening his grip, tears still burning at the corner of his eye, voice hoarse and patchy when he growled again.

“I gave you ONE job and instead you break my fucking solit-mmmmmmm.” Another one, his belly was starting to transform into something rounder, but still not near capacity. He glowered, keeping it shorter _. “Who else knows you’re in here_?”

“I gave the guys their jobs. I got bored when there weren’t enough assignments to go around.” Killer tried to keep his eyes on Nightmare’s face, but his stomach was far more interesting. “Figured I’d see what was so special or I’d get zapped.”

Nightmare could scarcely hold the glare as more and more pushed in. The more full he was, the harder it was to focus on anything else. He threw the other skeleton roughly across the room.

“Flip that last fucking switch, or I swear to god, I’ll - haaah!” His body leaned heavier onto the footrest. 

Killer turned his head towards the door. There were a set of switches by the wall, so he walked over and flipped the last one into place with the others. He could feel the magical barrier pop up now. He couldn’t leave.

Nightmare fought to keep himself any type of presentable, but he knew he was failing. He did this alone for a reason. And after so many nights of this, he couldn’t deny how good it felt and was an even more shaky mess with the idea of it. The gentle glide across his sensitive walls as it slid into him, stretched just beyond what was comfortable set his soul on fire.

He came to startled, a hand on his belly pulling him out of his haze with a yelp.

“How many even fit in there?” Killer had bent over him front behind, rubbing the way he’d seen the tentacle do. He could feel the weight packed tightly into Nightmare’s body. “You’re already so big…”

“GET YOUR HANDS OFF OF M-eeeeeeee!” Nightmare felt another drop into his body. Killer’s hands massaged his stomach into place, physically feeling his ecto stretch a little farther directly under his fingers. Nightmare went to reprimand, but another had dropped close together, his thighs quivering while he was tended to.

“I’d take ya if your body wasn’t so occupied already.” He ran some fingers over the tentacles thrusting into their owner. “Though…” His hand dipped down from his belly, towards his entrance. “I noticed you haven’t cum yet.” He dragged a finger over Nightmare’s clit softly, Nightmare bucking and whining with the attention. “Don’t know how, I about did just watching ya.” Killer’s pace was soft and steady. He could feel his cock throb for each time Nightmare cried out.

“FUCK Y-YOU!” Nightmare tried to push Killer’s hands away, but he was too weak to dislodge him with his arms by now. His tentacles had all his power and they weren’t behaving. “Get OFF!”

“Nah. If I’m dying for watching anyway, I’m gunna have good time.” Killer slid hard across his slit again, watching Nightmare throw his head back keening. “Though, I’m up for suggestions if something’ll help.”

Nightmare shook under Killer’s attentive fingers. One hand worked him, the other soothed his belly as the…? egg dropped in. (He’d lost count, but somewhere near twenty. The eggs weren’t very large though, and he’d been forced to take more than double that before.) Nightmare’s hand joined his, massaging the other half of his stomach, adamentally ignoring Killer’s presence as best he could. The pleasure built up in him slowly at first, ratcheting up with each little pop. His peak came suddenly, overwhelmed by the unfamiliar sensations.

“Oooooh!” His pussy clenched painfully around the intruding tentacle, cyan magic leaking out around the intrusion. “AH!” Killer’s hand wiped up some of the mess before cleaning his hand with his tongue.

“So sweet. Was expecting something more bitter.” His grin didn’t falter, Nightmare growling ferally underneath him. He grabbed the tentacle buried inside Night firmly. 

“I’m going to _enjoy_ dusting you.” Nightmare moved his hips around, still stuck on the thing. Killer laughed near his ear.

“I’m gunna enjoy every moment before that boss.” And Killer left him like that, stuffed and overstimulated, but a temporary respite from everything else. He hadn’t understood what the point of it was, getting frustrated at being forced to endure this humiliation if the eggs were done until he felt Killer release their carrier. “Moan with that pretty mouth of yours for me.”

Nightmare’s breath caught in his throat. He’d only delayed the eggs, not stopped them, and now there were five or so, all pressing into him at once.

His entrance was still sensitive, spasming around the eggs as they forced their way inside one after the other rapidly. Killer’s hands warmed his aching body, seating the new additions as best he could while Nightmare screamed out his name. His mind fuzzed over, too out of it to care anymore. His whole body trembled violently, his tentacles moving on their own accord.

The free one picked up Killer and moved him in front of Night’s body. Its master couldn’t speak, so it followed the orders in Nightmare’s mind instead.

Killer looked over surprised at his boss’s face when his pants were forcibly dropped. His red ectocock sprang up in front of Night’s face, and he only got a stern glare ( _if you speak a word of this_ , _I’ll torture you until you beg for death_ ) before opening his mouth.

He stepped forward and Nightmare took it into his throat in one go.

“Fuck.” Killer’s hand ghosted over Night’s head. Push him too far, and his dick would be bitten off. “You feel so good…”

Nightmare forced his eye closed. If he had to have Killer here, he’d try to ignore him as best he could, pretending his body had replaced the tentacle in his mouth, but clearly some things couldn’t be ignored. The taste in his mouth was completely different and he could hear Killer quietly huffing. It helped when Killer began to thrust into his open mouth, his mind blanking out in an instant.

Killer tried to keep pace with the tentacle in Nightmare’s ass, the one his mouth tentacle had been matching before. His reward, watching Nightmare resume his earlier antics, definitely made his cock throb.

Night’s tongue did put some effort into pressing up on Killer’s cock, but what was really fucking him up was the visuals. He didn’t want to blink.

Nightmare’s throat was loosened and open, drool haphazardly dripping out of his mouth, tears finally falling, moaning intensely around his cock as more and more eggs kept pushing him tighter and tighter. He was so full now. His belly strained against the amount of eggs shoved into his ecto, eye hazy and unfocused. Killer’s pace increased automatically. 

“Look how many there are…” He cupped Night’s cheek, who leaned into it instantly. “You’re really fucking impressive boss.” The whine made Killer moan. “God damn gorgeous.”

The last egg was descending slower than the others, and Killer growled, using Nightmare’s mouth hard and fast to finish when that round little thing sank home.

“Take it. Take it like you’ve taken everything else.” Nightmare’s eye flicked up to his face, unfocused but biting, and Killer came down his throat with ‘boss’ on his lips. 

The tentacles pulled out of Nightmare, as did Killer, but he couldn’t move, hand clumsily trying to reach his entrance, close to another orgasm.

“Ahhhhhhhhh. So tight…” His hand didn’t make it, rubbing his belly overwhelmed.

Killer got the message anyway.

He dropped down to sitting on the ground, right behind Night’s dripping thighs, and stuck his tongue inside.

“KILLER!” Nightmare’s mouth screamed out his name again and again. The tongue massaged the abused walls, taking in the flavor, while Killer’s less clumsy hand worked itself into his folds and to his clit. He hummed as he worked, his boss absolutely losing his mind until he felt a splatter of liquid right onto his waiting face.

When he pulled his face back, he cleaned the mess with his tongue hungrily. 

“What a treat.” He sighed happily. 

Nightmare’s body sagged, leaning sideways until he was on the floor. His hands tried to help his aching stomach adjust. His tentacles usually helped him, but they were very unhelpful at the moment. He felt a blanket drop over him and a body press up to his back. Killer’s hand joined his, soothing his ecto.

“I’m still going to kill you.” Nightmare’s voice was weak, unconvincing. Killer laughed against his shoulder.

“I know. So chill out, no one will know ya let me comfort you if I’m dead.”

Nightmare’s eye closed, breathing in shakily. Then he intertwined his hand with Killer’s. They kept rubbing over his belly, but together. Killer hummed softly.

“It takes a few hours for my body to release them.” He found himself saying quietly. He’d never been able to share this with anyone. “Laying them is harder. Takes much longer than implanting them.”

“What do ya usually do while waiting?” Killer’s voice softly reached him while he felt tiny kisses along his collarbone.

“Relax, eat something, find a comfortable place to lay.” His body felt too tired to put up a front. Killer had a point; if he was dust anyway, might as well enjoy his company and relax. He hadn’t allowed himself to be this weak in front of others in centuries. The luxury of it was calming.

Nightmare slowly sat, groaning at the effort. Killer steadied him, offering a hand after he stood up first.

He pulled the blanket around his body. He’d need it as his bones got colder. Nightmare sat gently on the couch, groaning as his stomach got tighter. Killer raised a brow at him.

“Did your tentacles shrink just now?”

“Are you going to question me for everything that my body undergoes?” Nightmare glared, but Killer’s eyes got wider.

“Holy shit, your other eye exists.” Nightmare’s face went cyan. Killer walked right up to him and stared. “I didn’t know you even had another, thought you lost the other one.” Night glared unhappily, pulling his blanket tighter around his frame.

“I suppose I’ll explain, but only so you’ll stop with the questioning. I can’t relax if you won’t be quiet.” He sighed, looking forward to killing him at the end of this. Killer waited patiently, though his grin got wider and wider the longer it took for Nightmare to get over his discomfort to speak.

“My corruption embeds itself in my body, feeding off my soul energy. Normally, it is sustained on negative emotions, but when the world grows too happy for too long, it needs strength from the apples I consumed long ago. I believe this ridiculous cycle it goes through is how it regenerates itself, and that is why it’s not a regular event. I’ve had it happen once in a year, and on a particularly bad spree, twice in a single month.” Nightmare tensed, curling around the center of his body. “It is why they’re harder to lay. My corruption filters into them, making them bigger.” His brows knitted together. He could feel his tentacles shrink further. After a few steadying breaths, he added. “I’ll be in my natural form before this ends.”

Killer tilted his head, approaching quietly. He knelt before him, his king, but couldn’t take off the crazy smile. 

“Can’t wait to see how cute you are under all the goop boss.” Nightmare glared ferociously, but Killer ignored it to stand. “Now, what kinda grub ya got in here? Since I’m stuck with ya, I suppose I could serve you like normal.” He wandered off towards the kitchen.

He was pretty sure that Nightmare was weakened to hell right now, and man, if he wanted a shot at killing the boss, he wasn’t getting another chance this in his favor. But something in his soul ached at the thought of killing him, which hadn’t happened since long before the resets began. His soul quivered, target shape shaking, but he just ignored it to keep his eyes facing the kitchen. Nightmare hated him and would probably kill him over cooperating, but damn if he wouldn’t try anyway for that little voice in the back of head saying to take care of _his_ Nightmare.

Killer rummaged through the cabinets, not a care in the world, when he heard Night quietly say, “pancakes. Dark chocolate chip pancakes.”

Heh, wonders never cease. He pulled out the ingredients and got to work.

——-

Nightmare came to leaned against Killer’s shoulder. After some warm pancakes (Killer could flip them as well as his knife it seemed), his eyes had drooped hard and sleep had taken him. His body was exhausted from the start of his ordeal, and it had to gain strength to finish the much harder part later on. He went to rub his face.

His corruption had fully come off. 

“Joining the living there Boss?” Nightmare froze, Killer had placed a hand on his cheek. “Let me get a look at ya.”

“You are not in charge of me, Killer.” Nightmare glared when the other tilted his head to the side anyway. He lamented the lack of tentacles to strangle him with. “I may not have the same face, but I assure you, I’m exactly who you remember threatening you before coming in this room.” His hands had strength again, he grabbed him by the throat.

“I know you liked being choked. Don’t need a demo.” His smile never faltered. Killer shrugged. “Can I please get a look at you? Consider it my dying wish.” He winked at Nightmare, who dropped his arms.

“Why? This body is disgusting, absolutely wretched in this state.” He pulled the blanket over his huge midsection, eggs full of corruption stretching out his now purple ecto. He frowned, pulling his face away. Killer moved to stand in front of him, wherever he tried to avoid looking. “There is NO reason for thi-” Killer pulled him up off the couch, the blanket slipping off his shoulders suddenly.

Nightmare crossed his arms over his chest, for a small feeling of being covered. Killer’s eyes raked over his form.

“Of course you’d be pretty.” Killer stroked over Nightmare’s humeruses. “You were a knockout with the corruption, shoulda known.” His hands rubbed over his egg filled body. “Even if I knocked ya up…”

“Shut up.” Nightmare flushed purple. 

“Sorry. Can’t help myself.” He tipped him forward in his arms, catching him against his hoodie, and pressed his teeth to Nightmare’s quickly.

Nightmare shivered in Killer’s arms, not sure how to feel about Killer kissing him in this form, in this state. He gasped when a finger caressed a line right up his spine. Killer snuck his tongue into the open mouth, snickering into the kiss with unrivaled glee. Nightmare’s eyes slid shut as the tongue massaged his. Killer’s arm locked around his waist, pressing his belly up into Killer’s waiting hand to soothe and stroke over it.

“Killer…” His knees felt weak. Killer just switched his mouth to his collarbone, nipping all over the exposed area.

“Do you know how bad I want you?” Killer whispered it over the bruised bone. “Ya call me your right hand, work with me personally all the time, walk that beautiful ass in front of my face day by day.” The hand slid from his belly down to his pussy, gently working Nightmare’s clit to slick him up. “Dust me if ya want to stop. Anything less I’ll take as a yes.”

Killer’s soul was still in place, and Nightmare could reach out and crush it without effort. The temptation of the taste of dread and despair as he died…it was almost enough when combined with the embarrassment and agitation of his minion speaking to him that way. 

Instead, he gripped the back of Killer’s head and snatched his attention.

“I guess you better do a good job then.” He pulled their teeth together, and Killer dove in without any hesitation.

With Nightmare’s blessing, his fingers slid deeper to plunge into his wet cunt.

“Nnnnngh.” He clung to Killer’s shoulders, bright purple blush lighting up his face while he awkwardly spread his legs further apart for the fingers to get deeper inside him. His stomach jutting out between them didn’t make anything easier. The fingers came out too quickly, Night whined but Killer held them up to lick clean.

“Sorry boss. Gotta move ya and then I’ll prepare you all nice for me. Promise.” He hefted him up, bridal style with a squeak. Wide eyes as his body jostled, the eggs shifting and moving suddenly making him moan sharply. His eyes watered as Killer moved them to the bed. He’d been so caught up, he’d almost forgotten the state he was in.

He was laid across the bed softly. His legs were parted by Killer climbing between them.

“You are clearly deranged.” Nightmare moaned, Killer’s fingers slipping right back in, adding a third. He huffed through the thrusting to demean Killer. “To want ME, especially like this.” Killer crooked his fingers, making Night pant. “Your taste is deplorable.”

“Nah, it’s pretty exquisite.” Killer stuck his tongue out, twisting his fingers inside at the same time. He shivered at the look on Night’s overwhelmed face. “Got a thing for a god. Can’t shoot much higher.”

“I’ll tell Dream after you die.” He choked when Killer jumped from three fingers to five.

“Don’t say shit like that.” His eyes dripped from the hate spilling over. It touched Night’s femurs, making his back arch from the feeding. Night’s purple eyes gathered tears in the corners. “I’d sooner fuck Ink, and I hate that asshole.” Killer licked his hand clean, groaning at the sweet purple nectar on his tongue.

“Stop the false flattery then. I’m already dusting you when this is over. Be honest.” He sneered, but Killer laughed loudly as he pulled his clothes off, tossing them to the side of the bed.

“Honest, huh?” His hands laid on Night’s bulging stomach. “You sure?”

“Completely.” Nightmare braced himself for whatever Killer would say, between shaky inhales from the warmth of his hands attentively massaging him.

“I might jerk off while you pop these out of your pussy boss.” His wide grin was the only answer to Nightmare’s shocked flush. He hauled Nightmare up into his lap, his cock already full erect, positioning him to slide down. “I’d be honored to be your throne.” He laughed and pulled him up as he fell on his back, Nightmare sitting speared on his cock while he got to lay back and just look at him. “What a fucking view.”

“Killer! Ahhh!” His tight walls ached at the fullness, the angle bouncing his heavy midsection with each thrust. Killer’s vice-like grip had his hips locked in, pulling him up firmly, then forcing him down quickly, hips flexing upwards to smash into him.

“It’s been, a few, hours, boss.” Killer’s tongue lolled out of head, staring at Night’s face. “Maybe they’ll, wanna start, while I fuck, the daylights out of you.” He could barely speak clearly, but Nightmare was worse. The rapid bouncing, the harsh pounding, and the hot fullness drowned all other senses. He might be close, and if he was, he might start the process on purpose over the rough treatment. Part of him worried, about many things, but the other frisky part spoke louder.

“ _Harder_.” Killer responded enthusiastically.

“You’re so fucking gorgeous. I wish I could have you like this everyday.” Killer panted as he pistoned in and out with increasing speed. “Fuck, I love you, fuck, fuck fuck, shouldn’t say that, fuck.” But Nightmare already had heard, tears actively falling now, all his nerves spiking in pleasure upon hearing it. His orgasm built closer and higher with the speed until he wailed. He convulsed hard, tongue tangling over Killer’s name, who came right into his tight pussy at the lewd display. 

Nightmare cried softly. He couldn’t move, his hips still held tight, his mind too muddled to say anything else.

He felt Killer twitch under his legs. His soul shuttered and turned into an inverted heart.

“You okay?” The hand on his cheek shocked him. Killer looked worried.

“I-I…AH!” His hands dropped to his stomach, a sudden cramp pulling him out of his thoughts enough to lean back. Killer popped out of him with a squish and rush of liquid.

This was earlier than usual. He’d never had sex during one of these either though, so maybe it just pushed him farther.

“Fuck, is it time?” Killer instantly got to piling up pillows for Night to lay back on. “I was kidding about it starting from that.”

“Apparently…m-my body was-sn’t.” Focus, focus. The pillows helped, but Night needed to move his legs, currently too close together to do anything. He held his breath through a cramp.

Killer appeared in front of him with his shorts on, sliding his legs apart and rubbing his belly. It was hard, tight like a drum, pressing down on the eggs to force them to start the descent. Nightmare sobbed as his body prepared to open up. Killer glanced at the thick black eggs through Night’s ecto, their girth doubled from when they went in. A few perhaps tripled.

“How can I help?” He couldn’t see Killer, his eyes shut from the pain. The first one was always the worst. “What do ya need?”

Nightmare’s hand shot out, snatching Killer’s tightly, whimpering while his body bared down. Killer held the small white hand in both of his grey ones. Night’s agony kept ratcheting up, sobbing openly while that first one slowly worked its way down. Killer peeked between his legs, it had barely descended enough to start parting his entrance. 

At the next pause, Night’s body was moved, to panicked crying after Killer released his hand.

“Shhhhh, I’m not going anywhere.” His back was now against Killer’s sturdy chest. His voice was feather soft, arms wrapping around to hold both of Nightmare’s hands. “I gotcha. You’ve got this.”

“I-I don’t n-nee-” Another wave crashed through his body, the egg pushing further down. He squeezed Killer’s hands tightly, leaning into him. It still had yet to crown. He sucked in air when the pain subsided.

“I know ya don’t need the help, you’ve done this alone plenty of times.” The voice was soft by his ear. He could feel the thrum of Killer’s soul against his back, pulses of worry that calmed Nightmare down. “But I’m here right now, you want the comfort and I’m offering.” He steadied Night through another wave, the egg so close to being free. “One more.”

He wanted to bite back (of course he knew how close he was!), but when that first egg finally popped free, his body shuddering and relieved, he positioned his arms to better accommodate Killer’s.

“They get easier. Stretching the path hurts.” His head fell back on Killer’s shoulder. “Thought you were going to “jerk off.”” He couldn’t stop the tired chuckle at Killer’s blush.

“The going in part looked like a good time. Didn’t know you’d be bawling your eyes out for this.” Nightmare felt a soft kiss on his cheek. “A little pain can be fun, that’s not this.” He held fast while another wave rolled through Night’s body.

“It can be, towards the end.” He pushed hard, nudging the eggs inside him downward. “That will take an hour at least though.” The second egg started the slow descent.

“Not my first concern, but if you’re offering…”Killer hummed at the cute purple blush. He went still for each wave he felt pass through Nightmare’s body, resuming the teasing of his boss’s back and shoulders with warm clanks.

Nightmare focused on the rhythm. Each push was easier than the last, his endurance high from how many times this had happened over his very long life.

None were so pleasant as this time, Killer’s touch calming him down, his mind at ease from the grounding presence. Company was something he seldom kept outside of necessity, the words of the past still stung even now, but perhaps he’d been hasty. Killer’s light caresses helped him find his center, using his inner muscles to force the eggs out. Time passed quickly, measured only in the growing pile between his legs. His entrance got used to the stretch. When the ninth finally exited, Nightmare let out a low whine.

“Feel good?” Killer’s thumbs rubbed the backs of Nightmare’s hands. He hadn’t been squeezing as hard.

“The thirteenth is always the best.” His cheeks lit up, turning away from Killer’s face. He hadn’t meant to say it.

“You’re on ten now, right?” Nightmare nodded, head tipping back while another egg slid down his canal. Within three pushes, it was already poking out of him. “Let’s count down to the best one then.” Killer released his hands, still keeping his arms around the pale skeleton, gentle strokes over his slightly smaller stomach. He bumped Night’s hands with his ulnas. He latched on again, steadily breathing through the next push. Ten fully crowned.

“Three left, this one is so close.” His hot breath made Nightmare’s vertebrae tingle. Killer’d gotten used to the rhythmic pulsing too. “Three…two…one.”

The wave hit immediately. Nightmare groaned as he pushed out the tenth. It popped out with a moan. He felt Killer’s tongue across his throat.

“Are you sure thirteen is the best? That sounded pretty good…” Nightmare’s hips arched, holding Killer’s arms in support. “Two more. You ready?” 

“Killer…” His mouth held the name, dropping the end into a purr as the eleventh started its journey. His body vibrated. The purring drove Killer wild, the sound soothing his soul. Nightmare’s head laid back so far against Killer’s shoulders. Killer tilted his head to grin at him.

“Yes?”

Nightmare’s eyes fluttered shut at the next pulse. Killer kissed him, he didn’t expect the hand locking him in. Nightmare opened his mouth for access, Killer not needing any further temptation to ravish him, tongue exploring to his heart’s content while Nightmare kept making satisfied little sounds.

“One more.” Nightmare’s voice had dropped to a whisper.

“Fuck, Nightmare.” Shit, he slipped up. He wasn’t supposed to call him that to his face, or much anywhere else, but he’d been too caught up to notice. The last person who’d slipped up had gotten thrown off the castle tower. Nightmare’s bright pupils dilated. “I mean, boss, I’m sorry, I-”

“Shut up.” He pulled their faces together. He took Killer’s mouth by force, tasting him greedily. He only paused when the urge to push overcame him, pulling back with a gasp. “Oooooh.”

His eyes rolled back into his skull as he bore down, the twelfth egg just barely visible through his slick ecto. Killer’s eyes blinked into white wide rings, hands straying down to the main event.

“How stretched are ya?” He slid a single finger in to the first knuckle before knocking against the black egg.

Nightmare made a strange keening sound, the tap against the egg sending shockwaves through his body. Killer swirled his fingers around the edges, tapping and tracing, stimulating Nightmare’s core until he cried out. He moved his hand back when he felt Nightmare squeeze down.

“You’re killing me with that mouth of yours.” The egg was held just shy of its widest points. Killer traced the edge again, now stimulating just outside Nightmare’s sensitive folds. He whimpered in Killer’s arms. “Just one more push, and we’ll be on the _best_ one.”

He nodded, dazed and edged. He took a deep breath. With a satisfying pop, the twelfth fell onto the bed.

“It’s already in place…”Nightmare whined, the egg sitting so low in his hips, his stretched magic already sliding open for the thirteenth. His tongue lolled out, not needing to push to feel its slow crawl down his body, wet and ready from the twelve before. Nightmare actively refrained from forcing it along to let his nerves burn in pleasure. His eyes slid closed as he moaned with reckless abandon.

Killer’s soul pinged against his back, along with something else. His teeth nipped at Nightmare’s collar. 

“Ride the wave love, I’m listening.” His fingers slipped back into Nightmare. His pussy opened for him, crooking them along the delicate inner walls, touching the gently descending egg. Nightmare’s eyes watered again, tears spilling at the overwhelming sensations and Killer’s deep voice behind him.

When it finally dropped to its thickest point, Nightmare pushed down for the sweet relief.

But it didn’t move.

He felt a hard tap shake the egg, sending shocks from where he was spread wide. Then it gently slid up, to Nightmare’s sharp inhale.

“If thirteen is your favorite, let’s enjoy it a little longer, hmm?” Killer sighed happily at Nightmare’s shaking frame clamoring up on his arms.

“Killer! Killer please! I-I-I NEED it OUT!” But Killer wouldn’t let it pass. He pushed it back inside, and then let it slide out to the widest point, over and over again while Nightmare clawed at his arms in overwhelmed tears. He spared Nightmare when his whines turned to sobs, rubbing along his clit while slowly fucking Nightmare with his own egg. Nightmare’s entrance tightened hard around the shell.

“Come for me Nightmare…” He whispered it into Night’s ear. He didn’t have to wait long for the shrill scream.

“KILLER!” He let the egg go, it popping out as Nightmare wailed. He spun around, gripping Killer’s shoulders firmly, settling onto his knees to stare into Killer’s face while he cried. Killer could hear the faint sounds of more pops, his body pushing down with the force of his orgasm. Nightmare whined, glaring at his face. Killer wiped away the tears.

“Couldn’t help myself. C’mere.” He pulled Nightmare close to the chest. 

He held up Night’s upper half, leaned forward and still pushing out the growing pile of eggs surrounding him. Night cried into his sternum, huddled up on his arms, Killer’s circling him in an embrace while he rode out the rest of the laying. He rubbed along Night’s spine in an effort to comfort him. Kissing his skull seemed to work just as well.

“It’s - ahhhh- almost over.” Nightmare’s breathing slowed down. Killer caught a glimpse from the side, the ecto belly almost as small as when he ported in here hours ago. He tilted up the purple face to catch it in a kiss.

“I’m gunna miss you Nightlight. Being dust is pretty boring.” Nightmare’s hand rubbed his ecto, feeling the last egg leave his strained body. He wanted to pass out. Collapsing against Killer revealed a little problem. “Sorry. Last display did a number on me.”

“You are quite the nuisance.” Nightmare sleepily murmured against his chest. “I am too tired to even think about helping you.”

“You don’t have to. I’ll just deal.” Killer’s groaned suddenly when his shorts were pulled down just enough to free his cock, Nightmare sliding on in one motion. He couldn’t hide the shock, jaw slack as the pale Nightmare smirked, threaded his arms behind his neck, and leaned up to whisper in his ear.

“You can use my body. You’ll just have to do all the work.”

Killer swallowed hard. His hands traced down Nightmare’s slim hips, free of corruption and implantations, but that same sassy attitude, eyes half lidded and sultry, even if there were two and they were purple instead. This was Nightmare. Purely his boss, down to the marrow. 

“Thanks for the gift love.” He winked at Nightmare’s soft blush. His hands held Nightmare’s hips, gently rubbing circles on them. He thrusted experimentally.

Nightmare panted gently, eyes meeting Killer’s. Nightmare was the most beautiful thing he’d ever seen.

Killer kissed him hungrily. He needed every bit of Nightmare he could have, pounding into his stretched ecto while eating up every sound. If this was the last thing he got before he died, there were a million worse ways to go than a passionate night with his god.

He didn’t part them until he came, moaning his love’s name. 

They had ended up clutched together, holding tight and as raw and real as they could be. Nightmare’s voice didn’t raise above a whisper.

“I don’t want to dust you.” He rested his forehead against Killer’s. His voice wavered, still small, afraid to break the moment. “But I don’t know if I’m capable of loving you back. I’m not the god of such positive emotion.”

Killer wasn’t one for soft moments, but he could read a room. He might never see Nightmare this unguarded again.

“You don’t have to love me back.” He stared into Nightmare’s eyes. “I’ll follow you anyway Nightmare. I didn’t think I’d tell you and we’d go on sappy dates every weekend, holding hands in some sunshiny AU out there. That’s not us, that’s not you.” He kissed him again. “If all I get is this night, it’s more than I expected.”

“How foolish you are, to fall for the god of negativity.” Nightmare sleepily fell against him, drained of everything. “When I awake, I’ll be corrupted once more.” Killer helped lower them, sideways, awkwardly on the top half of the bed away from the pile of eggs still residing in the bed’s lower end. He pulled out and slid his god against him. “Thank you.”

“Anytime.” But Nightmare shook his head, trying to fight his eyelids as he laid to rest.

“Thank you for loving me.” The last thing he heard was the quiet rumble of Killer’s chest.

“ _Love you too Nightlight_.”

——

When Nightmare sat up, his body had returned to normal. His tentacles snapped happily along his back. He could sense the AUs far from his home, clouded with misery and despair, and his body let go of the deep seated ache. 

The ordeal was completed and negativity was on the rise.

He wasn’t where he had fallen asleep, having been placed on the couch under his blanket. The apartment was clean, tidy, all signs of yesterday’s event gone from the floor. 

He yawned as he stood, seating his hands in his pockets while his tentacles resumed their job. They opened the door to the bedroom.

Similarly clean. Not a mark.

The only thing missing was Killer. His eye drifted to the switches, one flipped off. He’d cleaned the place and left him to wake up alone. He sneered at the notion that a simple clean up would earn him his life back. (A tiny voice denied him, reminding him of yesterday, but he shut it out.) He opened the door without ceremony, ready to return to the outside world.

He climbed the stairs, returning to the main living areas with a few open doors.

“Heya Boss!” Cross waved at him from the table. He’d been playing poker with Dust, losing terribly if the chips were anything to go by.

“Hi Boss.” Dust’s greeting was much more subdued, distracted, by the game or his brother, he didn’t know. He heard a tiny ‘hmph’ of greeting from Error on the couch and Horror had spaced out looking at the ceiling. Still not the face he needed to see.

“I see you all finished up quickly. I can sense your work already spreading across many souls. Good job. I will plan an efficient plan to capitalize on this by tomorrow. You’ve earned a free day.” 

They all grinned wide, half of them jumping up out of their seats.

“Really?! Maybe I’ll go see a movie…” Cross rubbed his chin while all the others made plans or walked off to their respective living quarters for a night’s rest. And only once all of them vanished did Killer walk in.

He refused to give Killer the satisfaction of knowing how badly it affected him to see his face again. 

“Got any assignments Boss? I didn’t have any to give myself yesterday.” Nightmare glared at him, the casual grin irking him. “Appreciate the free day, but I’m a little stir crazy.”

“Well considering you didn’t get any work done yesterday, the bigger punishment would be making you do nothing it seems. You don’t do well without channels for that destructive energy.” Nightmare grinned right back, liking the twitch of irritation at the corner of Killer’s mouth. “I think you need a lesson in following directions, so please do stay in today. If I find out that you’ve disobeyed me, the consequences will be _severe_.”

Killer shivered but his face didn’t drop the manic grin.

“As you wish Boss.” He shrugged, ready to walk away, acting like nothing had changed like he knew Nightmare would prefer. Boss letting him keep his head was pretty generous. He didn’t expect a tentacle to wrap him up tight, yanking him backwards.

“And Killer?” Killer tilted his head, being held upside down in front of Nightmare. The tentacle tightened around his bones.

“Do make plans to assist me in further cleanses. I think it might benefit my corruption to torture someone during the process. Do NOT disappoint me.” His soul vibrated with the energy.

“Never Boss. Just say the word.” And he was set down, Nightmare walking towards his office without turning back.

His eye twitched while he fought to keep his soul a target. Nightmare was choosing him back, even if he downplayed it. His god was recognizing him, his love, choosing him over all the others. Suddenly, sitting inside didn’t feel all that bad.

After all, he’d be in for some _good_ times from now on.


End file.
